(吉首大學(xué) 生物資源與環(huán)境科學(xué)學(xué)院，吉首 416000)
摘 要: 采用流變相法結(jié)合控制熱處理制備添加釔(Y)的LiNi0.5Mn1.5O4材料(LiNi0.5-0.5zMn1.5-0.5zYzO4)，研究釔添加量對LiNi0.5Mn1.5O4的結(jié)構(gòu)、形貌、導(dǎo)電率以及電化學(xué)性能的影響。結(jié)果表明：添加適量的Y可抑制LiNi0.5Mn1.5O4顆粒的長大，穩(wěn)定LiNi0.5Mn1.5O4的結(jié)構(gòu)，提高材料的電導(dǎo)率，降低循環(huán)過程中的電化學(xué)極化，最終有效地提高LiNi0.5Mn1.5O4的循環(huán)性能和倍率性能。在研究范圍內(nèi)，添加量z為0.02時(shí)，材料LiNi0.49Mn1.49Y0.02O4具有最好的電化學(xué)性能。在0.2C放電時(shí)，LiNi0.49Mn1.49Y0.02O4的首次放電容量達(dá)到132.7 mA？h/g，經(jīng)100次循環(huán)后，平均每次循環(huán)的容量衰減僅為0.011%。而在5.0C和10.0C放電時(shí)，LiNi0.49Mn1.49Y0.02O4仍顯示出優(yōu)異的倍率性能，首次放電容量仍達(dá)到0.2C放電時(shí)電容量的80.9%和76.9%，分別為107.3 mA？h/g和102.1 mA？h/g。
關(guān)鍵字: LiNi0.5Mn1.5O4材料；流變相法；高電壓；釔添加；鋰離子電池
（College of Biology and Environmental Science, Jishou University, Jishou 416000, China）
Abstract:LiNi0.5Mn1.5O4 materials with Y addition (LiNi0.5-0.5zMn1.5-0.5zYzO4) were prepared using rheological phase method combining with controlled heat-treatment. The effects of Y content on the structure, surface morphology, conductivity and electrochemical properties were investigated. The results show that the cycling performance and rate capability of LiNi0.5Mn1.5O4 materials will be improved effectively because that Y addition can suppress the growth of LiNi0.5Mn1.5O4 particles, stabilize the structure of LiNi0.5Mn1.5O4, increase the electronic conductivity of the electrode materials and decrease the electrochemical polarization in cycle. The materials with z of 0.02 show the best electrochemical properties. The first discharge capacity of LiNi0.49Mn1.49Y0.02O4 is more than 132.7 mA？h/g, an average capacity loss per cycle is 0.011% after cycling at 0.2C for 100 times. Even discharging at 5C and 10C, LiNi0.49Mn1.49Y0.02O4 still delivers a discharge capacity of 107.3 mA？h/g and 102.1 mA？h/g, equaling to 80.9% and 76.9% of the discharge capacity at 0.2C, suggesting excellent rate capability of LiNi0.5Mn1.5O4 with Y addition.
Key words: LiNi0.5Mn1.5O4 material; rheological phase method; high voltage; Y addition; lithium ion batteries
